Air-cooled sewing machine

ABSTRACT

An improved sewing machine construction in which the machine is encircled within a pair of envelopes and the lubricant sump is formed with cooling fins which define passages through which cooling air is directed from a suitable source that delivers air between the pair of envelopes and the machine body.

United States Patent 1191 [111 3,779,188

Marforio 1 Dec. 18, 1973 [54] AIR-COOLED SEWING MACHINE 2,762,324 9/1956 1168s 112 256 3,486,474 12/1969 Kosrow et [75] Inventor: Nerm M113, Italy 2,126,230 8/1938 Troxell 112/218 R x [73] Assignee: S.p.A. Virginio Rimoldi & C., Milan,

Italy Primary Examiner-H. Hampton Hunter 2 Filed; May 1 1972 A110mey-John R. Bronaugh et al.

[21] Appl. No; 254,376

[57] ABSTRACT gd An improved sewing machine construction in which [58] Fie'ld "Hi R 256 the machine is encircled within a pair of envelopes and the lubricant sump is formed with cooling fins which define passages through which cooling air is directed from a suitable source that delivers air between [561 References Clted the pair of envelopes and the machine body.

UNITED STATES PATENTS 3,638,594 2/1972 Armstead, Jr. et a1. 112/218 R 6 Claims, 3 Drawing Figures I 3O 4O 12 III l W 1 l 11/ T l L l/ 26 2121 2s as PATENTEU DEC 18 I975 SIEEI 1 OF 3 PATENIED on: 18 1973 SHEET 2 0F 3 PAIENIEDBEB 18 4975 SHEET 3 0F 3 AIR-COOLED SEWING MACHINE The present invention relates to an air-cooled sewing machine whose frame includes a base, a standard fixed on the said base, a lubricant sump fixed under the base and pneumatic devices for the circulation of the cooling air.

In the field of the sewing machines some lubricant cooling systems are already well known; the cooling is required to keep the main characteristics of the lubricant practically unchanged during a prolonged working of the machine. A first system consists in designing a cooling coil for the cooling air let in the lubricant to be cooled. As the air has the outside temperature, it removes the heat given by the lubricant passing in the cooling coil.

This system, however good it is, has the trouble of its being cumbersome in relation to the limited size of the lubricant sump where it is mounted.

A second system consists in connecting the lubricating circuit of the sewing machine with a common radiator. The lubricant, is cooled perfectly, however the whole system requires the use of a quantity of lubricant much greater than usually.

As the oil change in the sewing machines having a lubrication circuit occurs quite frequently, it is clear that the greater the quantity of lubricant circulating is the higher the cost of its change is. The incidence of this cost is more felt because the increase of lubricant in the circuit is caused by the greater length of the pipes and the increased capacity of the collection vessels and not by the greater request of lubricant by the driving devices to be lubricated.

Finally, a third well known system is designed to send a stream of air against a partition wall, which is inside the frame so as to remove the heat just near the area where it is higher.

The difficulty of this system is due to the scarce capacity of dispersion of the partition wall because of its thickness which is rather great. This is due to the fact that it is usually used as support for rolling bearings or bushings of the rotary shafts of the machine.

The aim of the present invention is to eliminate the troubles of the well known systems and this to assure a satisfactory coiling of the lubricant in the sewing machines. In order to achieve this aim, the technical problem to be solved was that to create the ideal conditions to obtain the almost whole dispersion of the heat given by the driving devices in the various points where it is generated'by making use of the traditional pneumatic means without tampering the frame of the sewing machine.

In order to solve this technical problem there has been constructed a sewing machine of the kind mentioned whose frame is encircledin envelopes forming an air space and pipes for the passage of the cooling air; they are connected with the pneumatic means so that the air put in circulation by these means laps on the walls passing thus removing their heat.

The main advantage offered by the present invention is that it is provided with a veil" of circulating air which encircles the frame so that the heat generated by the driving devices is not only removed when the lubricant gets to the collection sump, but it is also removed from all the points where it is possible to have a circulation of cooling air.

The present invention relates to an industrial sewing machine of the overlock type and its aims and advantages are those which are inherent and which will become apparent from the following detailed description of a preferred embodiment of realisation which description is referred to the accompanying drawings, wherein:

FIG. 1 shows a partially sectioned longitudinal view of the machine in question;

FIG. 2 shows the same machine seen from the side of the handwheel;

FIG. 3 shows a section of the FIG. 1 according to the line III-III;

With special reference to the FIG. 1, a sewing machine includes a frame 10 usually formed by a base 11 and on it a hollow standard 12 fitted with a head 13 capable to conventionally support a needle bar 14 provided with a needle clamp 15 and a needle 16. On the side of the standard 12, on the base 11 there is designed a work plate 17 on which the fabric slides as it is sewn by the machine.

Lower down, the base 11 supports a sump 18 in which the lubricant circulating in the machine is collected to make it cool at the end of its cycle.

Inside the base 11 the main shaft 19 is supported and can turn.

It is provided on the free end jutting out of the frame with a handwheel 20 fitted with a transmission pulley 21 which can be connected with the usual driving means of the machine (not shown).

The rotations of the pulley 21 are transmitted through suitable driving means to the needle 16 which therefore moves alternatively in a vertical direction. The sewing machine thus constructed is also provided with a lubricating circuit (not shown) which keeps the high efficiency of the said driving devices.

The main task of the lubrication is to reduce the friction between the contact surfaces and to keep the temperature of these parts low removing most of the heat they generate.

In order to fulfil this task, the sewing machine has a cooling circuit in which the collection sump 18 is fitted with cooling fins 22. They are parallel and at a distance between themselves and, starting from the right side wall 23 of the sump, spread out along the lower wall 24 ending on the left inclined wall 25. The fins 22 form with the walls 23, 24, and 25 of the sump some grooves for the passage of the cooling air. The sewing machine is also fitted, near the hadwheel 20, with the pneumatic means 26 represented by a centrifugal ventilator whose fan wheel 27 is keyed on the main shaft 19.

Besides the fan wheel, the centrifugal ventilator includes also a scroll part or diffusor 28 fitted with an inlet mouth 29.

During the working of the machine, the pneumatic means generate an air stream around the inlet mouth 29 so that, to improve this stream and increase its cooling force, the said inlet mouth faces the standard 12 and the latter is completely encircled by an envelope 30, which is slightly at a distance so as to form a air space. The said air space acts as a pipe along which the the sucked air passes through slots formed between the envelope 30 and the standard 12 all around the latter.

Therefore, the air passes through the said slots and touches the walls of the standard as the arrows show, so that the upper part of the frame 10 is kept at a sufficiently low temperature.

Part of the air is sucked by the centrifugal ventilator 26 directly from the outside through a grating 32 fitted with openings 32 and placed near the handwheel of the machine. In this way it happens that the air, sucked directly from the outside through the openings 32 mixes with the air sucked through the said air space thus partially removing the heat it has collected passing between the standard 12 and the upper envelope 30.

The air, once inside the diffusor 28, passes to the grooves designed between fin and fin 22 of the sump 18. To increase the cooling power of the air and not to disturb the use of the sewing machine, the collection sump 18 is encircled in a lower envelope 33 which forms, in co-operation with the walls of the said sump, a series of pipes. More exactly, it forms the pipes 34 between fin and fin and two wide pipes 35 and 36 in cooperation with the front wall 37 and, respectively, the back one 38 of the said sump. The blown in air stream; passing through the pipes and the conductor, removes most of the heat accumulated by the lubricant in its cycle, thus leaving to the stream passing in the cavity wall on the standard 12 the task to eliminate the residual heat of the recycled lubricant.

Finally, the air gets back to the outside through an opening 38 (FIG. 1) made between the lower envelope 33 and the wall 25 of the sump. It is oriented in a way that it does not disturb the user of the machine, so that there is such an orientation that the said opening is practically parallel to the main shaft 19 of the machine.

A further means to assure completely the elimination of the residual heat is represented by an upper cap 39 of the standard 12, which is fitted with cooling fins 40 (FIGS. 1 and 3).

As the recycled lubricant passes inside this cap, the air passing between the fins 40 eliminates even the smallest quantity of residual heat.

I claim:

ll. Air-cooled sewing machine whose frame includes a base, a standard fixed on the said base, a lubricant collection sump fixed under the base and pneumatic means for the circulation of the cooling air characterized by the fact that the frame is encircled in upper and, respectively, lower envelopes (30, 33) forming a single air space and pipes (34, 35, 36) connected with the pneumatic means (26) so that the air put into circulation by the latter touches the walls of the frame thus removing the residual heat.

2. Sewing machine according to claim 1, characterized by the fact that the standard (12) of the frame (10) is fitted with an upper cap (39) with cooling fins (40) between which the air sucked by the said pneumatic means (26) passes; the said upper cap (39) being designed in the air space formed by the upper envelope (30) and the said standard (12) of the frame (10).

3. Sewing machine according to claim 1, characterized by the fact that the pipes (34, 35, 36) are formed by the combination of cooling fins (22), placed at a distance in the collection sump (18) of the lubricant of the said frame (10), with the outer walls (23, 24, 25, 37, 38) of the said sump (19) and with the lower envelope (33).

4. Sewing machine according to claim 3, character ized by the fact that an outlet opening (38) is designed between the lower envelope (33) and the left wall (25) of the sump (18), placed practically parallel to the main shaft (19) of the machine; said opening (38) being placed, in respect of the said sump (18), on the opposite side of the pneumatic means (26).

5. Sewing machine according to claim 1, characterized by the fact that the pneumatic means (26) include a centrifugal ventilator whose inlet mouth (29) is oriented towards the standard (12) thus favouring the passage of the air through the said air space.

6. Sewing machine according to claim 1, characterized by the fact that near the handwheel (20) of the machine there is designed a grating (31) fitted with openings (32) directly connected with the outside; the openings (32) being designed to make the air pass which mixes with the air sucked by the said pneumatic means (26) through the air space between the frame (10) and and the upper envelope (30) so as to remove partially the accumulated heat from this part.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,779,188 Dated December 18, 1973 lnvenunxs) Nerino Marforio It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

rp --1- On page containing Abstract, Column 1, Line 9, after 254,376, insert Claims priority, Application Italy,

June 17, 1971, 25943 A/7l.

Column 1, Line 46, change "coiling" to --cooling--.

Column 2, Line 20, change "plate" to --plane--.

Signed and sealed this 30th day of July 1974.

(SEAL) Attest:

MCCOY M. GIBSON, JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

1. Air-cooled sewing machine whose frame includes a base, a standard fixed on the said base, a lubricant collection sump fixed under the base and pneumatic means for the circulation of the cooling air characterized by the fact that the frame (10) is encircled in upper and, respectively, lower envelopes (30, 33) forming a single air space and pipes (34, 35, 36) connected with the pneumatic means (26) so that the air put into circulation by the latter touches the walls of the frame thus removing the residual heat.
 2. Sewing machine according to claim 1, characterized by the fact that the standard (12) of the frame (10) is fitted with an upper cap (39) with cooling fins (40) between which the air sucked by the said pneumatic means (26) passes; the said upper cap (39) being designed in the air space formed by the upper envelope (30) and the said standard (12) of the frame (10).
 3. Sewing machine according to claim 1, characterized by the fact that the pipes (34, 35, 36) are formed by the combination of cooling fins (22), placed at a distance in the collection sump (18) of the lubricant of the said frame (10), with the outer walls (23, 24, 25, 37, 38) of the said sump (19) and with the lower envelope (33).
 4. Sewing machine according to claim 3, characterized by the fact that an outlet opening (38) is designed between the lower envelope (33) and the left wall (25) of the sump (18), placed practically parallel to the main shaft (19) of the machine; said opening (38) being placed, in respect of the said sump (18), on the opposite side of the pneumatic means (26).
 5. Sewing machine according to claim 1, characterized by the fact that the pneumatic means (26) include a centrifugal ventilator whose inlet mouth (29) is oriented towards the standard (12) thus favouring the passage of the air through the said air space.
 6. Sewing machine according to claim 1, characterized by the fact that near the handwheel (20) of the machine there is designed a grating (31) fitted with openings (32) directly connected with the outside; the openings (32) being designed to make the air pass which mixes with the air sucked by the said pneumatic means (26) through the air space between the frame (10) and and the upper envelope (30) so as to remove partially the accumulated heat from this part. 